363] LARVAE OF THE TENTHREDINOIDEA—YUASA 45 



35(26) Anal larvapods united on the meson forming a single protuberance; antennae with 

 one segment; third abdominal segment with two annulets; prothorax often with 

 dorsal and ventral shields; vertical furrows wanting; head and body depressed, 

 glabrous SCOLIONEURINAE. 



36(25) Larvapods wanting on ultimate segment; vertical furrows wanting 37. 



37(38) Antennae with three segments; third abdominal segment with four annulets, annulets 

 2 and 3 setiferous; tenth abdominal tergum with a caudo-mesal protuberance; body- 

 not depressed HOPLOCAMPINAE (in part). 



38(37) Antennae with 1-2 segments; third abdominal segment with two annulets, annulets 

 glabrous; tenth abdominal tergum without a caudo-mesal protuberance; body 

 depressed FENUSINAE. 



39(24) Thoracic legs with 3-4 or 6 segments; larvapods on abdominal segments 2-7 and 10 

 or 2-6 and 10, very small 40. 



40(41) Mesothoracic and metathoracic legs with six segments; prothoracic legs with six 

 segments; larvapods on abdominal segments 2-7 and 10 and occasionally with a 

 rudimentary eighth pair, or 2-6 and 10; body dilated laterad, sublateral lobe pro- 

 duced and conspicuous, often with numerous setiferous tubercles. HYLOTOMINAE. 



41(40) Mesothoracic and metathoracic legs with three segments; prothoracic legs with 

 four segments; larvapods on abdominal segments 2-7 and 10 with an occasional 

 rudimentar)' eighth pair; body not dilated laterad, sublateral lobe not produced 

 and conspicuous; body never with numerous setiferous tubercles but with minute 

 protuberances SCHIZOCERINAE. 



42(1) Thoracic legs not normal in form, but fleshy, indistinctly four-segmented, tarsal 

 claws wanting; larvapods vestigial on abdominal segments 2-8 and 10, ultimate 



pair united on the meson, forming a single protuberance 



PHYLLOTOMINAE (in part). 



Subfamily Diprioninae 



Larvae (Fig. 7) moderately large, length 18-25 mm.; body cylindrical, 

 somewhat robust, tapering gradually caudad; segmentation and annula- 

 tion distinct; third abdominal segment with six annulets, annulets 1, 2, 

 and 4 or 2 and 4 with setae and glandubae; larvapods on abdominal 

 segments 2-8 and 10, close together on the meson; thoracic legs normal, 

 well developed, with five segments; prothoracic legs distinctly smaller than 

 other legs; color of body usually yellowish or greenish, with grayish, or 

 brownish stripes or rows of black spots; antennae with three segments, seg- 

 ments 1 and 2 minute, flat, irregular, incomplete, segment 3 erect, peg-like, 

 strongly chitinized; head and legs usually with spinous, stiff setae; glandu- 

 bae prominent and numerous; ventral glands wanting; spiracles not winged; 

 cuticle microscopically spinulate; larvae feed on conifers. 



The subfamily Diprioninae is represented in North America by three 

 genera, Diprion, Neodiprion, and Monoctenus. The Neartic species 

 formerly placed in the genus Diprion (Lophyrus) are placed by Rohwer 

 (1918a) in Neodiprion. Diprion simile Hartig of Europe has recently 

 become estabhshed in the United States. With the exception of Mac- 

 Gillivray, systematists agree in associating the genus Monoctenus with 

 Diprion and its allies. 



